Film gate structure



Sept. 26, 1933. F. J. Loomis 1,928,455

FILM GATE STRUCTURE v Filed May 10, 1930 ai m91. ,y F122.

Inventor' Fred J; L oornLs 3 bg HLs Attorneg.

Patented Sept. 26, 1933 PATENT OFFICE FILM GATE STRUCTURE Fred J. Loomis, Haddonfield, N. J., assigner to General Electric Company, a corporation of New York Application May 10, 1930. Serial No. 451,446

7 Claims.

My invention relates to motion picture machines and particularly to that part of such a machine which is commonly known as the gate structure. It is one object of my invention to provide an improved gate structure which is of simple and rugged construction, convenient to operate and inexpensive to manufacture. An other object of my invention is to provide a gate lo structure having improved means for yieldingly holding the film in proper position during its passage therethrough.

My invention will'be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 is a side view of a gate embodying my invention; Fig. 2 is a cross sectional view of the same taken on line 2-2 of Fig. 1; and Figs. 3 'and 4 show details thereof.

In the drawing the frame member 1 of the gate structure through which the light is projected is arranged to be secured, for example, by the 25 screws 2 to the part 3 of the frame of the picture projector. Telescoping within one end of the frame 1 is the objective mounting 4 which by means of the guide pin 5 slidably mounted in the frame 1 may be adjusted for focusing purposes. Adjustment of the member y4 may be effected by the turning of the adjusting screw shown at 6. At the opposite end of the frame is the fiat film engaging face plate 7 over which the film 8 is caused to slide intermittently during the 5 projection of the pictures. Where the film first engages the plate v7 it is guided laterally by roller 9 having end flanges between which the film runs.

For further guiding the film the plate 7 is provided with lateral guide strips 10 and 11 of which the 40 latter is spring mounted in the well known manner. The frame 1 is also provided with the detachable aperture plate or mask l2.

For yieldingly pressing the film against the plate 7 I have provided the gate 14 which comprises the backing plate to which film engaging shoes are yieldingly attached. In the drawing I have shown three separate and independent pairs of shoes 16, 17 and 18. The three pairs of shoes, while shown of various lengths, are' essentially the same in construction and in their resilient mounting on the backing plate. As shown more clearly in Figs. 3 and 4, shoes 16 are connected to the backing plate by means of two rectangular sheet metal members 2G and 21 having central openings therein. These members may be constructed of any suitable resilient ma.-

terial such, for example, as spring steel. Shoes 16 are attached to member 20 at the upper and lower portions thereof, members 20 and 21 are connected together by means of the short studs 22 at intermediate points of their side portions, 60 and member 21 is secured to the backing plate by the short studs 23 at intermediate points of its upper and lower portions. As a result of this construction the shoes are free to yield bodily and to rock in response to the passage of splices in the film. They are prevented, however, from having any longitudinal movement or lateral movement. Moreover, either shoe may yield without substantially affecting the pressure applied by the other shoe. The openings in the rectangular sheet members to which shoes 17 are attached are in alignment with an opening in the backing plate 15 and the opening in the aperture plate 12.

The right angle extension 25 of the backing plate is arranged to slide in a suitable guideway formed at the rear of the frame 1 from which the gate may be bodily removed when desired by simply withdrawing the extension 25 from the frame. For moving the gate to the open position shown by Fig. 1, I have provided the hollow spring pressed plunger 26 which slides in a suitable opening in the frame 1. For moving the gate from the open position to the closed position in which the shoes yieldingly press the film against the plate 7, I have provided the hand lever 27 35 which is secured to one end of the shaft 28 mounted in the frame 1. At the opposite end of this shaft is the arm 29 which is adapted to engage the pin 30 on the extension25. Thus by turning the hand lever 27 in a counter-clockwise direction as the apparatus is viewed in Fig. 1, the gate will be shifted to the closed position against the force of the spring pressed plunger 26. For holding the gate in the closed position, I have mounted in the frame 1 the sleeve 31 in which slides 95 vthe rod 32 having at one end the knurled button 33 and at the other the flange 34 from which projects the eccentric pin 35. A small coil spring 36 serves to yieldingly hold the eccentric pin against the extension 25. This member is provided with a slot 37 which is properly positioned to receive the eccentric pin when the gate is moved to closed position. In order to permit a certain amount of adjustment of the pressure applied to the film by the shoes, the operating pin 32 is provided with a small cross pin 38 which is arranged to slide in a longitudinal slot formed in the sleeve 31 so that by turning the knurled button 33 the position of the eccentric pin can be changed to vary the closed position of the gate. Various means may be provided for frictionally retaining the sleeve 31 in the frame 1. For this purpose I have shown by way of example, the notched bolt 39 and nut 40. In the use of the gate structure which I have shown and described, the gate is moved from the open position illustrated to the closed position by the operation of the hand lever 27, the catch mechanism automatically retaining gate in the closed pos!- tion with the shoes applying the desired pressure on the lm. When the gate is to be opened the operator merely withdraws the knurled button 33 enough to release the extension 25 when the spring pressed plunger 26 immediately pushes the gate to the opened position.

I have chosen the particular embodiment described above as illustrative of my invention and it will be apparent that various modifications may be made without departing fromthe spirit and scope of my invention, which modifications I aim to cover by the appended claims.

What I claim as new and desire to obtain by Letters Patent of the United States is:

1. A lm gate structure comprising a supporting frame, a cooperative gate including a backing plate having lm engaging shoes resiliently mounted thereon and an extension having sliding engagement with the frame, and means for adjustably latchingl the gate in closed position comprising a member rotatably mounted in the frame and having an eccentric portion adapted to engage a portion of said extension and means for retaining the member in adjusted position.

2. A lm gate structure comprising a supporting frame, a cooperating gate including a backing plate having lm engaging, shoes resiliently mounted thereon and an extension having sliding engagement with the frame, and an adjustable latching device for retaining the gate in a predetermined closed position comprising a pin having an eccentric mounting in the frame and arranged to engage a portion of said extension, means for rotatably adjusting the mounting of said pin and means for frictionally retaining said mounting in adjusted position.

3. A film gate structure comprising a supporting frame, a cooperating gate including a backing plate having film engaging shoes resiliently mounted thereon and an extension having sliding engagement with the frame, and an adjustable latching device for retaining the gate in a predetermined closed position comprising a rotatably adjustable sleeve mounted in said frame, an eccentric pin supported thereby arranged. to engage a portion of said extension, and means for rotating said sleeve and withdrawing said pin from engagement with the extension.

4. A film gate structure comprising a supporting frame, a cooperating gate including a backing plate having hlm engaging shoes resiliently mounted thereon and an extension having sliding engagement with the frame, and an adjustable latching device for retaining the gate in a predetermined closed position comprising a rotatably adjustable sleeve mounted in said frame, an eccentric spring pressed pin supported thereby and arranged to engage a portion of said extension, and a single operating handle for withdrawing the pin from engagement with the extension and for turning the sleeve to adjust the closed position of the gate.

5. A film gate comprising a backing plate having means for attaching it to a cooperating front plate, a plurality of shoes adapted to engage the edge portions of a film and arranged to extend longitudinally thereof, and means connecting the shoes and the backing plate comprising a resilient plate secured adjacent its transverse edges to said shoes, and a resilient member secured to said resilient plate at points thereof adjacent to its longitudinal edges and intermediate its transverse edges and to said backing plate at points intermediate the longitudinal edges of the resilient plate.

6. A film gate comprising a backing plate having means for attaching it to a cooperating front plate, shoes adapted to engage a iilm at opposite edge portions thereof and arranged to extend longitudinally thereof, and means supporting the shoes from the backing plate comprising a plurality of spaced rectangular resilient plates secured together at points intermediate their longitudinal edges, the shoes being secured to one of said plates at points adjacent to its transverse edges and the backing plate being secured to another of said plates at points intermediate the transverse edges thereof.

7. A lm gate comprising an apertured backing plate having means for attaching it to a cooperating apertured front plate, shoes arranged at opposite sides of the aperture in the backing plate being adapted to engage a lm at opposite edge portions thereof and arranged longitudinally of the film, and means for supporting the shoes from the backing plate comprising a pair of similar rectangular plates having openings therein which are in alignment with the aperture in the backing plate, said plates being secured together in spaced relation at intermediate portions of their longitudinal sides, one of said plates being secured at its transverse portions to said shoes and the other of said plates being secured at intermediate parts of its transverse portions to said backing plate.

FRED J. LOOMIS. 

